11.2 Trace

When a function is traced, it means that every call to that
function is reported to the user during a program run. This can help a
programmer determine whether a function is being called at the wrong
time or with the wrong set of arguments.

trace function

Function

Enable debug tracing on function. While a program is being run, Guile
will print a brief report at each call to a traced function,
advising the user which function was called and the arguments that were
passed to it.